Keens Mill
New Jersey State Park

Keens Mill

Hamp Road, Delaware Township, New Jersey 08530
Available Activities
  • Hiking
  • Camping
  • Swimming
  • Fishing
  • Boating

New Jersey’s Historic Gristmill — Built by George Keen in 1838, Site of Revolutionary War-Era Mills, Swartswood Lake Area, Stillwater Township Sussex County New Jersey

Keens Mill is a historic mill site in the Swartswood Lake area of Stillwater Township, Sussex County, New Jersey. The mill was constructed by George Keen in 1838 on the site of an earlier mill established by Charles Rhodes. The location has hosted milling operations dating back to the Revolutionary War era, making it one of the longest-running mill sites in Sussex County. The site features a historic stone gristmill structure, connections to the broader Swartswood Lake recreational area, proximity to Swartswood State Park, and interpretation of New Jersey’s agricultural and industrial heritage.

Milling Heritage

Water-powered gristmills were the economic engines of rural New Jersey in the 18th and 19th centuries. The Keens Mill site exemplifies this heritage — with mills operating here since the Revolutionary War era, generations of Sussex County farmers relied on this location to grind their grain into flour. George Keen’s 1838 mill building represents the mature period of water-powered milling technology in northern New Jersey.

Swartswood Lake Area

Keens Mill sits near Swartswood Lake, one of the largest natural lakes in New Jersey and home to Swartswood State Park. The area offers excellent fishing, boating, swimming, and hiking, making it a natural complement to a visit to the historic mill site. The broader Stillwater Township area preserves much of its rural agricultural character, offering a glimpse into the landscape that sustained communities like the one that depended on Keens Mill.

ℹ️ Note: Keens Mill is a historic site, not an active recreational park. Nearby Swartswood State Park offers full recreational facilities.

Frequently Asked Questions

Is Keens Mill open to the public?

The mill is a historic site. For current access information, contact the Historical Society of Stillwater Township.

What is nearby?

Swartswood State Park is nearby, offering swimming, boating, fishing, camping, and hiking.

Wildlife & Nature

Keens Mill — a historic mill site in the New Jersey park system. The mill’s stream, pond, and surrounding forest support great blue herons, wood ducks, and painted turtles. Brook trout may inhabit the cold stream.

Nearby Attractions

Local New Jersey communities — surrounding.

Keep exploring: The closest neighbors are The Marshall House (a short drive away) and Delaware and Raritan Canal State Park Trail (a short drive away).

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Last updated: May 13, 2026

Park Location

Hamp Road, Delaware Township, New Jersey 08530